This application is based on and incorporates herein by reference Japanese Patent Application No. 2002-295013 filed on Oct. 8, 2002.
1. Field of the Invention
The present invention relates to a motor, which has a speed reducing mechanism and a circuit board received in a gear housing.
2. Description of Related Art
A motor, which has a circuit board received in a housing is disclosed in, for example, Unexamined Japanese Patent Publication No. 2002-262516.
The motor disclosed in this publication includes a motor main body and a speed reducing unit, which are connected together. The speed reducing unit includes a speed reducing mechanism. The motor main body includes an armature, which is rotatably received in a yoke housing. A brush holder is installed to an opening of the yoke housing. The brush holder holds power supply brushes, which are in sliding engagement with a commutator of the armature.
The speed reducing unit includes a gear housing, which is made of a resin material. The gear housing includes a wheel receiving portion, a circuit board receiving portion and a connector case. The wheel receiving portion receives a worm wheel, which constitutes a part of the speed reducing mechanism that reduces rotational sped of a rotatable shaft of the motor main body. The circuit board receiving portion receives the circuit board, which has a circuit that drives and controls the motor. The connector case is connected with the circuit board receiving portion in an axial direction of the rotatable shaft. The circuit board includes a connector main body, which has terminals. Furthermore, the circuit board is installed to the brush holder in the axial direction of the rotatable shaft to establish electrical connection with the brushes. When the motor main body is installed to the gear housing in the axial direction of the rotatable shaft, the circuit board is installed into the circuit board receiving portion in the axial direction of the rotatable shaft, so that there is formed a motor-side connector to be connected with the external connector.
However, in the above motor, when the connecting direction (i.e., the inserting direction) of the motor-side connector relative to the external connector needs to be changed due to a change in the corresponding design specification, a shape of the gear housing, in which the connector case is integrally formed, needs to be changed or modified. Such a modification of the shape of the gear housing generally has significant influences on the arrangement of the components received in the gear housing, so that such a modification of the shape of the gear housing cannot be achieved easily. To address such a disadvantage, it is conceivable to arrange the motor-side connector separately from the gear housing. Furthermore, in such a case, the inserting direction of the circuit board relative to the brush holder, which is positioned between the motor-side connector and the brush holder (the brushes), needs to be optimized. Also, it has been demanded to minimize manufacturing costs of the motor by addressing the above disadvantages.
The present invention addresses the above disadvantages. Thus, it is an objective of the present invention to provide a motor, which has an optimized position of a motor-side connector and an optimized installing direction of the circuit board and is capable of minimizing manufacturing costs of the motor.
To achieve the objective of the present invention, there is provided an electric motor including a motor main body, a speed reducing unit and a circuit board. The motor main body includes a rotatable shaft, which is rotated upon energization of the motor main body. The speed reducing unit is connected to the motor main body and includes a speed reducing mechanism and a gear housing. The speed reducing mechanism reduces rotational speed of the rotatable shaft. The gear housing receives the speed reducing mechanism. The circuit board is held in the gear housing and has a circuit, which controls rotation of the rotatable shaft of the motor main body. The gear housing includes a circuit board receiving portion, which opens toward the motor main body and receives the circuit board. The motor main body further includes a brush holder, which supports a plurality of power supply brushes and includes a motor-side connector to be connected with an external connector. The motor-side connector is integrated into the brush holder. The circuit board is installed to the brush holder in a direction perpendicular to an axial direction of the rotatable shaft to electrically connect between the motor-side connector and the power supply brushes. The circuit board is received in the circuit board receiving portion when the motor main body and the speed reducing unit are assembled together.
To achieve the objective of the present invention, there is also provided an electric motor including a motor main body, a speed reducing unit and a circuit board. The motor main body includes a rotatable shaft, which is rotated upon energization of the motor main body. The speed reducing unit is connected to the motor main body and includes a speed reducing mechanism and a gear housing. The speed reducing mechanism reduces rotational speed of the rotatable shaft. The gear housing receives the speed reducing mechanism. The circuit board is held in the gear housing and has a circuit, which controls rotation of the rotatable shaft of the motor main body. The gear housing includes a circuit board receiving portion, which opens toward the motor main body and receives the circuit board. The motor main body further includes a brush holder, which supports a plurality of power supply brushes and includes a connector case. The connector case is integrated into the brush holder. The circuit board includes a connector main body, which cooperates with the connector case of the brush holder to form a motor-side connector to be connected with an external connector. The circuit board is installed to the brush holder in a direction perpendicular to an axial direction of the rotatable shaft to electrically connect between the motor-side connector and the power supply brushes. The connector main body is inserted into the connector case in the direction perpendicular to the axial direction of the rotatable shaft to form the motor-side connector. The circuit board is received in the circuit board receiving portion when the motor main body and the speed reducing unit are assembled together.